There have heretofore been proposed various percutaneous absorption type pharmaceutical preparations which are formed by incorporating a medicine in a polymer substance having a pressure-sensitive adhesive property at room temperature (e.g., about 20.degree.-30.degree. C.) (e.g., an adhesive substance) and providing it on a support.
Recently, it has been attempted to incorporate a medicine in a polymer substance in a higher concentration than the solubility thereof in the polymer substance, so as to better ensure pharmaceutical effects and to increase the amount of medicine per unit area. However, such excess incorporation of an active ingredient can create a serious problem, viz., a reduction in the pressure-sensitive adhesive property of the polymer substance, due to crystallization of the active ingredient on the surface of the polymer substance layer formed on the support.
Therefore, it has alternatively been attempted to increase the thickness of the polymer substance layer, with the concentration of the active ingredient being under the solubility limit for the polymer substance, thus increasing the amount of active ingredient to be fed per unit area. This attempt, however, has the defects that sufficient pharmaceutical effects do not occur due to an insufficient amount of active ingredient per unit volume, or that an increased adhesive property to the skin causes pain upon peeling off of the preparation.